Have had fruit flies in the lab and they tend to travel home (what a pain). The best trap I have used so far is to set out a short glass with apple cider vinegar and place either a small spouted funnel on top (spout downward but not actually touching the vinegar) or you can make a paper cone with a small opening at the tip. The little flies are lured inside with the vinegar (apple cider does work best at least for me) and get inside but have a hard time getting out. Eventually they drown.

Most gas stations like Casey's, America, Exxon, etc. have small paper cones (free) for putting oil in your car, would those work?

My Orkin guy told me to put a tablespoon full of bleach down every drain in the house, including the bathtub/shower drains & overflow holes on bathroom lavatories. This is where they breed. He said to put it down the drain before you go to bed at night, DO NOT run any water, until the next moring. This will wipe out their breeding gound. Try to avoid getting the bleach on the chrome parts, remove them, if possible.

What I did is take a short (rocks) glass, put about 1/4 inch of apple cider vinegar in the bottom, covered with plastic wrap, then poked 5 or so holes with a ball point pen. The first day there was about a dozen in there. I changed the vinegar and then I went out of town, but DH said there was a few more in there, and I don't see any more buzzing around! This was seriously a lifesaver! I put the "trap" right next to the counter where I have a tray for tomatoes, and "warm" fruits like peaches and mangoes.